Has anyone got any good resources for something like this? I haven't touched C in years, and never worked on anything game-like. But it does look like a really interesting project to start something like this.
Even if you're using C you don't need to implement your own renderer or do half the things he does. Get a library like SDL3 to handle the basics, maybe use Lua/LuaJIT for scripting. Learn OpenGL or Vulkan. Stay away from HH and Casey Muratori until you're experienced enough to tell the difference between his wisdom and his bullshit.